Men presumably always have looked at flowers and been moved by their beauty and their smell: but only since the last century has it been possible to take a flower in your hand and know that you have between your fingers a complex association of organic compounds containing carbon, hydrogen, oxygen, nitrogen, phosphorus, and a great many other elements, in a complex structure of cells, all of which have evolved from a single cell; and to know something of the internal structure of these cells, and the processes by which they evolved, and the genetic process by which this flower was begun, and will produce other flowers; to know in detail how the light from it is reflected to your eye; and to know the details of those workings of your eye, and your nose, and your neurophysiological system, which enable you to see and smell and touch the flower. These inexhaustible and almost incredible realities which are all around us and within us are recent discoveries which are still being explored, while similar new discoveries continue to be made; and we have before us an endless vista of such new possibilities stretching into the future, all of it beyond man’s wildest dreams until almost the age we ourselves are living in. Popper’s ever present and vivid sense of this, and of the fact that every discovering opens up new problems for us, informs his theoretical methodology. He knows that our ignorance grows with our knowledge, and that we shall therefore always have more questions than answers.